<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>021Vue中CSS动画原理</title>
  <script src="./vue.js"></script>
  <style>
    .fade-enter,
    .fade-leave-to {
      opacity: 0;
    }

    .fade-enter-active,
    .fade-leave-active {
      transition: opacity 3s;
    }
  </style>
</head>

<body>
  <div id="root">
    <transition name="fade">
      <div v-show="show">hello world</div>
    </transition>
    <button @click="handleBtnClick">切换</button>
  </div>
  <script>
    var vm = new Vue({
      el: "#root",
      data: {
        show: true
      },
      methods: {
        handleBtnClick: function () {
          this.show = !this.show;
        }
      },
    })
  </script>
</body>

</html>